No. Apple updates are digitally signed by Apple with a key only they possess. This is also why jailbreaking an iPhone is so difficult. Nobody else has that key

No. Apple updates are digitally signed by Apple with a key only they possess. This is also why jailbreaking an iPhone is so difficult. Nobody else has that key, so the best you can do is find a bug in something Apple approved and try to gain root with it. There hasn’t been one of those in… years… and as for one that will allow an unsigned persistent update? Not since iOS 9. Almost a decade ago. Nobody has found a persistent jailbreak since. The last true chip exploit, which Apple cannot patch, was with the A10 Fusion seven years ago. It also required a USB cable, a Mac to inject the payload, and you had (and have) to connect the phone to the Mac every time you reboot it because it can’t persist itself.